We are playing the Guess Game. The game is as follows:
我们正在玩猜猜游戏。 游戏如下：
I pick a number from 1 to n. You have to guess which number I picked.
我从1到n中选择一个数字。 你必须猜测我选择了哪个号码。
Every time you guess wrong, I‘ll tell you whether the number is higher or lower.
每次你猜错了，我都会告诉你这个数字是高还是低。
You call a pre-defined API guess(int num) which returns 3 possible results (-1, 1, or 0):
您调用预定义的API guess（int num），它返回3个可能的结果（-1,1或0）：
-1 : My number is lower 1 : My number is higher 0 : Congrats! You got it!
Example :
Input: n = 10, pick = 6
Output: 6
1 /* The guess API is defined in the parent class GuessGame. 2 @param num, your guess 3 @return -1 if my number is lower, 1 if my number is higher, otherwise return 0 4 int guess(int num); */ 5 6 public class Solution extends GuessGame { 7 public int guessNumber(int n) { 8 int i = 1, j = n; 9 while(i < j) { 10 int mid = i + (j - i) / 2; 11 if(guess(mid) == 0) { 12 return mid; 13 } else if(guess(mid) == 1) { 14 i = mid + 1; 15 } else { 16 j = mid; 17 } 18 } 19 return i; 20 } 21 }
二分搜索法
136.Guess Number Higher or Lower
原文：https://www.cnblogs.com/chanaichao/p/9588285.html